News tagged with visible spectrum

Invisibility carpet cloak can hide objects from visible light

(PhysOrg.com) -- Most of the invisibility cloaks that have been demonstrated to date conceal objects at frequencies that are not detectable by the human eye. Designing invisibility cloaks that can conceal ...

Physics / General Physics

created Jun 15, 2011 | popularity 5 / 5 (20) | comments 22 | with audio podcast feature

Nano-LEDs emit full visible spectrum of light

(PhysOrg.com) -- Physicists from Taiwan have designed and fabricated nano-sized light-emitting diodes (LEDs) that emit light spanning the entire visible spectrum. Although the tiny full-color LEDs aren't intended ...

Nanotechnology / Nanophysics

created Jun 17, 2011 | popularity 4.9 / 5 (18) | comments 2 | with audio podcast feature

Novel negative-index metamaterial that responds to visible light designed

A group of scientists led by researchers from the California Institute of Technology has engineered a type of artificial optical material—a metamaterial—with a particular three-dimensional structure such that ...

Physics / Optics & Photonics

created Apr 22, 2010 | popularity 4.8 / 5 (43) | comments 10 | with audio podcast

A breakthrough for terahertz semiconductor lasers

(PhysOrg.com) -- Potential applications, says an engineering professor, include disease diagnosis and detection of concealed explosives.

Physics / General Physics

created Jan 13, 2011 | popularity 3.5 / 5 (11) | comments 3 | with audio podcast

Trapping a rainbow: Researchers slow broadband light waves with nanoplasmonic structures

A team of electrical engineers and chemists at Lehigh University have experimentally verified the "rainbow" trapping effect, demonstrating that plasmonic structures can slow down light waves over a broad range of wavelengths.

Physics / Optics & Photonics

created Mar 14, 2011 | popularity 4.5 / 5 (2) | comments 1 | with audio podcast

Mantis shrimps could show us the way to a better DVD

(PhysOrg.com) -- The remarkable eyes of a marine crustacean could inspire the next generation of DVD and CD players, according to a new study from the University of Bristol published today in Nature Photonics.

Physics / Optics & Photonics

created Oct 25, 2009 | popularity 4.9 / 5 (19) | comments 5

Berkeley Researchers Light Up White OLEDs

(PhysOrg.com) -- Light-emitting diodes, which employ semiconductors to produce artificial light, could reduce electricity consumption and lighten the impact of greenhouse gas emissions. However, moving this ...

Nanotechnology / Nanophysics

created Apr 06, 2010 | popularity 4.4 / 5 (21) | comments 7 | with audio podcast

Trifid triple threat

Smouldering several thousand light-years away in the constellation of Sagittarius (the Archer), the Trifid Nebula presents a compelling portrait of the early stages of a star's life, from gestation to first ...

Space & Earth / Astronomy

created Aug 26, 2009 | popularity 4.2 / 5 (5) | comments 8

Metal oxides hold the key to cheap, green energy

Harnessing the energy of sunlight can be as simple as tuning the optical and electronic properties of metal oxides at the atomic level by making an artificial crystal or super-lattice 'sandwich' says a Binghamton ...

Nanotechnology / Nanomaterials

created Apr 19, 2012 | popularity 4.9 / 5 (10) | comments 0 | with audio podcast

Researchers change the color and shape of a single photon

(PhysOrg.com) -- A team of researchers from the CNST and ITL has simultaneously changed the color and shape of a single photon, the smallest unit of light.

Physics / Optics & Photonics

created Oct 06, 2011 | popularity 4.5 / 5 (6) | comments 4 | with audio podcast

Scientists solve mystery of colorful armchair nanotubes

(PhysOrg.com) -- Rice University researchers have figured out what gives armchair nanotubes their unique bright colors: hydrogen-like objects called excitons.

Nanotechnology / Nanomaterials

created Jan 09, 2012 | popularity 5 / 5 (2) | comments 2 | with audio podcast

Scientists Build First 'Frequency Comb' To Display Visible 'Teeth'

(PhysOrg.com) -- Finally, an optical frequency comb that visibly lives up to its name. Scientists at the University of Konstanz in Germany and the National Institute of Standards and Technology in the U.S. ...

Physics / General Physics

created Oct 29, 2009 | popularity 4.9 / 5 (18) | comments 0

Dark matter: Physicists may have found piece of the puzzle

European astronomers said on Wednesday that an anomalous energy signal detected by an orbiting satellite could be a telltale of the enigmatic substance known as dark matter.

Physics / General Physics

created Apr 01, 2009 | popularity 3.9 / 5 (27) | comments 29

Discovery of an Unexpected Boost for Solar Water-Splitting Cells

(PhysOrg.com) -- A research team from Northeastern University and the National Institute of Standards and Technology has discovered, serendipitously, that a residue of a process used to build arrays of titania ...

Nanotechnology / Nanomaterials

created Apr 22, 2009 | popularity 5 / 5 (22) | comments 1

New 'broadband' cloaking technology simple to manufacture

(PhysOrg.com) -- Researchers have created a new type of invisibility cloak that is simpler than previous designs and works for all colors of the visible spectrum, making it possible to cloak larger objects ...

Physics / General Physics

created May 20, 2009 | popularity 4.9 / 5 (26) | comments 4

Visible spectrum

The visible spectrum is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 380 to 750 nm. In terms of frequency, this corresponds to a band in the vicinity of 790–400 terahertz. A light-adapted eye generally has its maximum sensitivity at around 555 nm (540 THz), in the green region of the optical spectrum (see: luminosity function). The spectrum does not, however, contain all the colors that the human eyes and brain can distinguish. Unsaturated colors such as pink, and purple colors such as magenta are absent, for example, because they can only be made by a mix of multiple wavelengths.

Visible wavelengths also pass through the "optical window," the region of the electromagnetic spectrum that passes largely unattenuated through the Earth's atmosphere. (Blue light scatters more than red light, which is why the sky appears blue.) The human eye's response is defined by subjective testing (see CIE), but atmospheric windows are defined by physical measurement.

The "visible window" is so called because it overlaps the human visible response spectrum. The near infrared (NIR) windows lie just out of human response window, and the Medium Wavelength IR (MWIR) and Long Wavelength or Far Infrared (LWIR or FIR) are far beyond the human response region.

Many species can see wavelengths that fall outside the "visible spectrum". Bees and many other insects can see light in the ultraviolet, which helps them find nectar in flowers. Plant species that depend on insect pollination may owe reproductive success to their appearance in ultraviolet light, rather than how colorful they appear to us. Birds too can see into the ultraviolet (300-400 nm), and some have sex-dependent markings on their plumage, which are only visible in the ultraviolet range.

For more information about Visible spectrum, read the full article at Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.